1. Technical Field
The present invention relates in general to a method and system for providing multiple paths to a computer network. More particularly, the present invention relates to a method and system for client computers to use multiple proxy servers in accessing web sites on the Internet.
2. Description of the Related Art
Computer systems in general and International Business Machines (IBM) compatible personal computer systems in particular have attained widespread use for providing computer power to many segments of today""s modern society. Systems with microprocessors are finding themselves in an array of smaller and more specialized objects that previously were largely untouched by computer technology. Computer systems typically include a system processor and associated volatile and non-volatile memory, a display area, input means, and often interfaces, such as a network interface or modem, to other computing devices.
One of the distinguishing characteristics of these systems is the use of a system board to electrically connect these components together. These computing devices are information handling systems which are designed primarily to give independent computing power to a single user, or a group of users in the case of networked computer systems. Personal computing devices are often inexpensively priced for purchase by individuals or businesses. Nonvolatile storage devices such as hard disks, CD-ROM drives and magneto-optical drives are also considered to be peripheral devices. Computer systems are often linked to other computing systems using a network, such as a local area network (LAN), wide area network (WAN), or other type of network such as the Internet. By linking to other computers, a computer system can use resources owned by another computing device. These resources can include files stored on nonvolatile storage devices and resources such as printers.
Servers perform different services for client computer systems. Web servers often provide content, or information, to client computers. Another type of server used by client computers is known as a xe2x80x9cproxy server.xe2x80x9d In an enterprise that uses the Internet, a proxy server is a server that acts as an intermediary between a client computer system and the Internet so that the enterprise can ensure security, administrative control, and caching service. A proxy server is associated with (or is part of) a gateway server that separates the enterprise network (often a local area network (LAN)) from the outside network (i.e., the Internet) and a firewall server that protects the enterprise network from outside intrusion.
A proxy server receives a request for an Internet service (such as a Web page request) from a user of a client computer system. If it passes filtering requirements, the proxy server (assuming it is also a cache server) checks Web pages that were previously downloaded by the proxy server. If the page is found, the proxy server returns the requested page to the user without needing to forward the request to the Internet. If the page is not in the cache, the proxy server, acting as a client on behalf of the user, uses one of its own IP addresses to request the page from the server out on the Internet. When the page is returned, the proxy server relates it to the original request and forwards it on to the user.
To the user, the proxy server is invisible; all Internet requests and returned responses appear to be directly with the addressed Internet server (i.e., Web server). (The proxy is not quite invisible; its IP address has to be specified as a configuration option to the browser or other protocol program.)
The functions of proxy, firewall, and caching can be in separate server programs or combined in a single package. Different server programs can be in different computers. For example, a proxy server may be in the same machine with a firewall server or it may be on a separate server and forward requests through the firewall.
Because of the role they play, proxy servers can be extremely busy machines. When a proxy server is too busy, it cannot efficiently handle all requests received from users. When this happens, the users have to wait for both the proxy server and the ultimate Web server to process the request, thus delaying the arrival of information at the user""s computer system.
More and more proxy servers are available to users. Many of these users have access to more than one proxy server. However, switching between available proxy servers often involves configuring the client computer system to direct requests to a different proxy server. A challenge in the current art, therefore, is switching between multiple available proxy servers based upon a given criteria.
In addition, one available proxy server may provide increased security when accessing confidential information, such as a client""s banking information, while another proxy may provide better general throughput or have a larger caching area to store documents of general public interest. A challenge with the prior art exists in correlating proxy servers with particular web addresses (URLs).
What is needed, therefore, is a method for automatically switching between two or more proxy servers based upon various conditions, or events, occurring in the system.
It has been discovered that providing a system and method for switching between multiple proxy provides a more efficient flow of data from servers to client computer systems. In one embodiment, the available proxy servers are automatically evaluated to determine the fastest proxy server available. The client computer system then automatically changes its configuration to direct requests to the fastest proxy server.
In another embodiment, a proxy table is accessed by the client computer to determine which proxy to use for a given web address. When a web address is included in the table, the corresponding proxy server is used to request the contents of the web address. If the web address is not included in the table, a default proxy server is used to request the information.
In yet another embodiment, a periodic test is made to determine the speed of the current proxy server. If the speed is less than a predetermined threshold, the available proxy servers are all tested and the best-performing proxy server is selected. In another embodiment, the above-described embodiments are combined to provide a proxy server to a client computer based upon either a given web address (URL) or the fastest current proxy server.
The foregoing is a summary and thus contains, by necessity, simplifications, generalizations, and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the present invention, as defined solely by the claims, will become apparent in the non-limiting detailed description set forth below.